This project is concerned with several aspects of conformation and orientation in a biological system. The significance of conformational changes associated with enzyme-substrate binding and catalysis is extremely important to a detailed understanding of the remarkable efficiency of the enzymatic process. The method involves the study of the motion of paramagnetic spin labels reporter groups incorporated at specific sites in the protein molecule of interest. In particular, we will be concerned with 1) elucidation of conformational homologues in the proteolytic enzymes alpha-chymotrypsin and trypsin, 2) investigations of the protein crystalline state and its changes upon chemical crosslinking, 3) structural investigations of insolubilized solid support linked enzymes and 4) structure-function investigations of lysozyme.